1. Field of the Invention
This invention relates to an agglutination analyzing vessel for analyzing agglutination patterns produced in response to immunological agglutination reactions and more particularly to a vessel for identifying various kinds of blood types with the aid of agglutination patterns of blood corpuscles or for detecting various kinds of antibodies and various antigens in sample solutions (like viruses, proteins or the like) with the aid of agglutination patterns of not only blood corpuscles but also of particles of materials such as latex, carbon or the like.
2. Description of the Prior Art
In a conventional method of identifying blood types, for example, which has heretofore been proposed, use was made of a winecup-shaped reaction vessel into which was quantitatively introduced a sample solution, 2 to 5% of test blood corpuscles suspended in saline solution, and a specified antiserum. Then, the mixture was set stationary for reaction between blood corpuscles and antiserum. Subsequently, it was centrifuged to sediment blood corpuscles. Then, the reaction vessel was rapidly wobbled such that the sedimented blood corpuscles were forcedly separated one from the other and then relatively slowly wobbled so as to collect the clumped compositions in the center portion of the base surface of the vessel and form settling patterns, and then photometrically detecting these patterns.
Such conventional blood type identifying method in which sedimentation is effected and then the reaction vessel is rapidly wobbled so as to separate the sedimented blood corpuscles from the base surface of the vessel can only be applied to the analysis of regular ABO blood type which shows strong agglutination, but could not be applied to many other immunological agglutination reactions which show weak agglutination, for example, a method of determining Rh blood subtype or detecting various kinds of incomplete antibodies. That is, if the agglutination reaction is weak, the blood corpuscles or the like which have been clumped together become separated one from other when the reaction vessel is wobbled, and as a result, the particles are not collected in the center portion of the reaction vessel.
In order to detect and measure the HBs antigen, a method has been proposed which makes use of a plastic plate, called microplate, provided with a number of wells each having a conical base surface. This conventional method makes use of a microplate having 10.times.12 wells, for example, and detects and prescribes the HBs antigen by the following procedure.
(1) Diluent specially prescribed for R-PHA method is introduced into each well of the microplate one drop (0.025 ml) at a time.
(2) A test serum (0.025 ml) is added to the first well of a row. By using a diluter, the doubling dilution is performed along the row up to the last (tenth) well.
(3) One drop of R-PHA cell (0.025 ml of 1% cell suspension) is added to each well.
(4) The mixture thus treated is sufficiently agitated by the micromixer for 10 seconds so as to cause the R-PHA cell to uniformly suspend.
(5) The mixture thus treated is left stationary at room temperature for one hour and thereafter the settling patterns are detected.
In such detection method, the reaction vessel is made sufficiently stationary before the detection so that the sedimented agglutinates are not separated one from the other. However, if this method is applied to an immunological agglutination reaction of one portion which is less stable than HBs antigen particularly to the agglutination reaction due to incomplete antibodies, it is impossible to obtain a sufficiently stable, clear and precise agglutination pattern. This is because of the fact that the agglutinated particles slip down along the conical base surface of the reaction vessel in the same manner as the particles which are not agglutinated and tend to be collected in the center portion of the vessel. In order to eliminate such drawback, use has been made of a reaction vessel provided at its conical base surface with ground glass like minute indentations. Such reaction vessel, however, is irregular in arrangement, size and configuration of the indentation, and as a result, too large an amount of agglutinates are collected in one portion of the inclined surface, thereby rendering formation of the uniform agglutination patterns difficult. Thus, it is not always possible to eliminate the above mentioned drawback.